Princeton Plasma Physics Laboratory Newshttp://www.pppl.gov/news/archive/2009
Princeton Plasma Physics Laboratory news feedenStewart Prager honored with FPA Distinguished Career Awardhttp://www.pppl.gov/news/2017/12/stewart-prager-honored-fpa-distinguished-career-award
<p>Stewart Prager, physicist and long-time fusion energy scientist who was director of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) from 2009 to 2016, has been honored with a 2017 Distinguished Career Award from Fusion Power Associates (FPA). Prager, a leading contributor to the advancement of plasma physics and fusion science, received the award at the 38th annual meeting of FPA held Dec. 6-7 in Washington, D.C. The association provides students, media and the public with information about the status of fusion development and other applications of plasma science.</p><p>The honor for Prager, a professor of Astrophysical Sciences at Princeton University, cited his “many years of dedication to advancing the prospects for fusion.” The citation pointed to his “decades of outstanding career contributions as a scientist, educator, manager, and advisor on all aspects of plasma physics, fusion energy and fusion policy.”</p><p>Fusion, the power that drives the sun and the stars, is the fusing of light elements that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power.</p>...December 12, 2017John Greenwaldhttp://www.pppl.gov/news/2017/12/stewart-prager-honored-fpa-distinguished-career-awardPhysicists win supercomputing time to study fusion and the cosmoshttp://www.pppl.gov/news/2017/12/physicists-win-supercomputing-time-study-fusion-and-cosmos
<p>More than 210 million core hours on two of the most powerful supercomputers in the nation have been won by two teams led by researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL). The highly competitive awards from the DOE Office of Science’s INCITE (Innovative and Novel Impact on Computational Theory and Experiment) program will accelerate the development of nuclear fusion as a clean and abundant source of energy for generating electricity and will advance understanding of the high-energy-density (HED) plasmas found in stars and other astrophysical objects.</p><p>A single core hour represents the use of one computer core, or processor, for one hour. A laptop computer with only one processor would take some 24,000 years to run 210 million core hours.</p><p><strong>“Extremely important and beneficial”</strong></p><p>“These awards are extremely important and beneficial,” said Michael Zarnstorff, deputy director for research at PPPL. “They give us access to leadership-class highest-performance computers for highly complex calculations. This is key for advancing our theoretical modeling and understanding.” Leadership-class computing systems ...</p>December 6, 2017John Greenwaldhttp://www.pppl.gov/news/2017/12/physicists-win-supercomputing-time-study-fusion-and-cosmosBlowing in the stellar wind: Scientists reduce the chances of life on exoplanets in so-called habitable zoneshttp://www.pppl.gov/news/2017/11/blowing-stellar-wind-scientists-reduce-chances-life-exoplanets-so-called-habitable
<p>Is there life beyond Earth in the cosmos? Astronomers looking for signs have found that our Milky Way galaxy teems with exoplanets, some with conditions that could be right for extraterrestrial life. Such worlds orbit stars in so-called “habitable zones,” regions where planets could hold liquid water that is necessary for life as we know it.</p><p>However, the question of habitability is highly complex. Researchers led by space physicist Chuanfei Dong of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and Princeton University have recently raised doubts about water on — and thus potential habitability of — frequently cited exoplanets that orbit red dwarfs, the most common stars in the Milky Way.</p><p><strong>Impact of stellar wind</strong></p><p>In two papers in The Astrophysical Journal Letters, the scientists develop models showing that the stellar wind — the constant outpouring of charged particles that sweep out into space — could severely deplete the atmosphere of such planets over hundreds of millions of years, rendering them unable to host surface-based life as we know it.</p><p>“Traditional definition and climate models of the habitable...</p>November 29, 2017John Greenwald http://www.pppl.gov/news/2017/11/blowing-stellar-wind-scientists-reduce-chances-life-exoplanets-so-called-habitablePPPL scientists deliver new high-resolution diagnostic to national laser facilityhttp://www.pppl.gov/news/2017/11/pppl-scientists-deliver-new-high-resolution-diagnostic-national-laser-facility
<p>Scientists from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have built and delivered a high-resolution X-ray spectrometer for the largest and most powerful laser facility in the world. The diagnostic, installed on the National Ignition Facility (NIF) at the DOE’s Lawrence Livermore National Laboratory, will analyze and record data from high-energy density experiments created by firing NIF’s 192 lasers at tiny pellets of fuel. Such experiments are relevant to projects that include the U.S. Stockpile Stewardship Program, which maintains the U.S. nuclear deterrent without full-scale testing, and to inertial confinement fusion, an alternative to the magnetic confinement fusion that PPPL studies. </p><p>PPPL has used spectrometers for decades to analyze the electromagnetic spectrum of plasma, the hot fourth state of matter in which electrons have separated from atomic nuclei, inside doughnut-shaped fusion devices known as tokamaks. These devices heat the particles and confine them in magnetic fields, causing the nuclei to fuse and produce fusion energy. By contrast, NIF’s high-powered lasers cause fusion by heating the exterior of the fuel pellet...</p>November 21, 2017Raphael Rosenhttp://www.pppl.gov/news/2017/11/pppl-scientists-deliver-new-high-resolution-diagnostic-national-laser-facilityPhysicist David Gates named editor-in-chief of Plasma, a new online journalhttp://www.pppl.gov/news/2017/11/physicist-david-gates-named-editor-chief-plasma-new-online-journal
<p>David A. Gates, principal research physicist and Stellarator Physics Division Head at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL), has been named editor-in-chief of Plasma, an online open access journal for plasma physics.</p><p>“I am excited to join the editorial board as editor-in-chief of Plasma and I look forward to helping advance the international research arena in plasma science,” Gates said. “This is an outstanding opportunity to help promote the research of a vital area of physics and to open the door to communicating that research to the global community.”</p><p>Plasma is an international, open access, peer-reviewed journal covering all aspects of plasma science, and will be published quarterly online by MDPI, an online publishing company based in Switzerland. <em>It is </em>a cross-disciplinary scholarly journal of scientific studies related to all aspects of plasma science, such as plasma physics, plasma chemistry and space plasma. It publishes reviews, research articles, short communications and letters. Topics also include experimental and theoretical results, and progress of interdisciplinary and application sciences in this field....</p>November 20, 2017Larry Bernardhttp://www.pppl.gov/news/2017/11/physicist-david-gates-named-editor-chief-plasma-new-online-journalPPPL honors Grierson and Greenough for distinguished research and engineering achievementshttp://www.pppl.gov/news/2017/11/pppl-honors-grierson-and-greenough-distinguished-research-and-engineering-achievements
<p>A breakthrough in the development of fusion diagnostics and the creative use of radio frequency waves to heat the plasma that fuels fusion reactions earned the 2017 outstanding research and engineering awards from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL). Physicist Brian Grierson and engineer Nevell Greenough received the honors from PPPL Interim Director Richard Hawryluk at a ceremony November 7 for their exceptional achievements.</p><p>Grierson received the Kaul Foundation Prize for Excellence in Plasma Physics Research and Technology Development for his groundbreaking measurements of the flow of the main atomic nuclei, or ions, in the DIII-D tokamak. DIII-D is a fusion plasma experiment operated by General Atomics for the Department of Energy in San Diego. The prize includes a $6,000 cash award endowed by former PPPL Director Ronald Davidson, who donated to Princeton University a portion of the gift he received as the 1993 recipient of the Award for Excellence in Science, Education and Physics from the Kaul Foundation in Tampa, Florida.</p><p>Greenough was named “Distinguished Engineering Fellow” for his creation of “high-power...</p>November 13, 2017John Greenwald http://www.pppl.gov/news/2017/11/pppl-honors-grierson-and-greenough-distinguished-research-and-engineering-achievementsPlasma from lasers can shed light on cosmic rays, solar eruptionshttp://www.pppl.gov/news/2017/11/plasma-lasers-can-shed-light-cosmic-rays-solar-eruptions
<p>Lasers that generate plasma can provide insight into bursts of subatomic particles that occur in deep space, scientists have found. Such findings could help scientists understand cosmic rays, solar flares and solar eruptions — emissions from the sun that can disrupt cell phone service and knock out power grids on Earth.</p><p>Physicists have long observed that particles like electrons and atomic nuclei can accelerate to extremely high speeds in space. Researchers believe that processes associated with plasma, the hot fourth state of matter in which electrons have separated from atomic nuclei, might be responsible. Some models theorize that magnetic reconnection, which takes place when the magnetic field lines in plasma snap apart and reconnect, releasing large amounts of energy, might cause the acceleration.</p><p>Addressing this issue, a team of researchers led by Will Fox, physicist at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), recently used lasers to create conditions that mimic astrophysical behavior. The laboratory technique enables the study of outer-space-like plasma in a controlled and reproducible environment. “We want to...</p>November 10, 2017Raphael Rosenhttp://www.pppl.gov/news/2017/11/plasma-lasers-can-shed-light-cosmic-rays-solar-eruptionsReaching new heights: Physicists improve the vertical stability of superconducting Korean fusion devicehttp://www.pppl.gov/news/2017/11/reaching-new-heights-physicists-improve-vertical-stability-superconducting-korean
<p>A major challenge facing the development of fusion energy is maintaining the ultra-hot plasma that fuels fusion reactions in a steady state, or sustainable, using superconducting magnetic coils to avoid the tremendous power requirement of copper coils. While superconductors can allow a fusion reactor to operate indefinitely, controlling the plasma with superconductors presents a challenge because engineering constraints limit how quickly such magnetic coils can adjust when compared to copper coils that do not have the same constraints.</p><p>The slower response time of these superconducting coils creates the problem. The slower pace makes it difficult to operate a stable discharge with the large plasma volume or extended vertical height required for producing fusion power. Exploration of this issue in a current superconducting device is particularly helpful for ITER, the international fusion experiment under construction in France, which will be operational in 2025.</p><p><strong>Leading edge of the challenge</strong></p><p>At the leading edge of this control challenge is the Korea Superconducting Tokamak Advanced Research (KSTAR) device, one of the largest superconducting...</p>November 6, 2017John Greenwaldhttp://www.pppl.gov/news/2017/11/reaching-new-heights-physicists-improve-vertical-stability-superconducting-koreanPPPL physicists win Edison Award for X-ray imaging inventionhttp://www.pppl.gov/news/2017/11/pppl-physicists-win-edison-award-x-ray-imaging-invention
<p>Three scientists from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have won an Edison Patent Award from the Research and Development Council of New Jersey for their invention of an imaging apparatus that could be used to produce the next generation of integrated circuits. </p><p>Physicists Manfred Bitter, Kenneth Hill, and Philip Efthimion are among 14 teams to win the 2017 Edison Patent Awards who will be honored at a Nov. 2 ceremony at the Liberty Science Center in Jersey City, New Jersey. It is the second consecutive year PPPL’ers have received the award. Last year, Charles Gentile, George Ascione and Adam Cohen received an Edison Award for their invention of an on-demand method to create a widely-used isotope used in medical imaging devices. </p><p>This year’s winners created an X-ray imaging apparatus that can be used for extreme ultraviolet light (EUV) lithography. “We are very grateful to have been selected for this award,” Bitter said. “It’s nice to come up with a new idea, if it is useful to somebody.” </p><p>The three scientists recently went to the library at the inventor’s home and laboratory at the Thomas Edison National...</p>November 3, 2017Jeanne Jackson DeVoe http://www.pppl.gov/news/2017/11/pppl-physicists-win-edison-award-x-ray-imaging-inventionThe blob that ate the tokamak: Physicists gain understanding of how bubbles at the edge of plasmas can drain heat and reduce fusion reaction efficiencyhttp://www.pppl.gov/news/2017/10/blob-ate-tokamak-physicists-gain-understanding-how-bubbles-edge-plasmas-can-drain-heat
<p>To fuse hydrogen atoms into helium, doughnut-shaped devices called tokamaks must maintain the heat of the ultrahot plasma they control. But like boiling water, plasma has blobs, or bubbles, that percolate within the plasma edge, reducing the performance of the plasma by taking away heat that sustains the fusion reactions.</p><p>Now, scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have completed new simulations that could provide insight into how blobs at the plasma edge behave. The simulations, produced by a code called XGC1 developed by a national team based at PPPL, performed kinetic simulations of two different regions of the plasma edge simultaneously. This ability produces a more fundamental and fuller picture of how heat moves from plasma to the walls, potentially causing damage.</p><p>“In simulations, we often separate two areas at the plasma edge known as the pedestal and the scrape-off layer and focus on one or the other,” said PPPL physicist Michael Churchill, lead author of a paper describing the results in the journal <em>Plasma Physics and Controlled Fusion</em>. “XGC1 is unique because it is able to simulate both...</p>October 19, 2017Raphael Rosenhttp://www.pppl.gov/news/2017/10/blob-ate-tokamak-physicists-gain-understanding-how-bubbles-edge-plasmas-can-drain-heatInnovative design using loops of liquid metal can improve future fusion power plants, scientists sayhttp://www.pppl.gov/news/2017/10/innovative-design-using-loops-liquid-metal-can-improve-future-fusion-power-plants
<p>Researchers led by the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have proposed an innovative design to improve the ability of future fusion power plants to generate safe, clean and abundant energy in a steady state, or constant, manner. The design uses loops of liquid lithium to clean and recycle the tritium, the radioactive hydrogen isotope that fuels fusion reactions, and to protect the divertor plates from intense exhaust heat from the tokamak that contains the reactions.</p><p>“There are many challenges to developing fusion energy and the handling of heat on divertor plates is among them,” said PPPL physicist Masa Ono, lead author of a paper about the design published in the journal <em>Nuclear Fusion</em>. “We wanted to see how we can protect the divertor plates and keep the fusion chamber clean.”</p><p>Fusion, the merger of light elements to release energy, is the process that powers the sun and stars. Here on Earth, fusion power plants will combine tritium with its sister isotope deuterium to create the energy for generating electricity. Producing this power in a fusion device is sometimes called “putting a star in a jar.”</p><p>The...</p>October 17, 2017John Greenwaldhttp://www.pppl.gov/news/2017/10/innovative-design-using-loops-liquid-metal-can-improve-future-fusion-power-plantsPPPL completes shipment of electrical components to power site for ITER, the international fusion experimenthttp://www.pppl.gov/news/2017/10/pppl-completes-shipment-electrical-components-power-site-iter-international-fusion
<p>The arrival of six truckloads of electrical supplies at a warehouse for the international ITER fusion experiment on Oct. 2 brings to a successful conclusion a massive project that will provide 120 megawatts of power – enough to light up a small city − to the 445-acre ITER site in France. </p><p>The Princeton Plasma Physics Laboratory (PPPL), with assistance from the Department of Energy’s Princeton Site Office, headed the $34 million, five-year project on behalf of US ITER to provide three quarters of the components for the steady-state electrical network (SSEN), which provides electricity for the lights, pumps, computers, heating, ventilation and air conditioning to the huge fusion energy experiment. ITER connected the first transformer to France’s electrical grid in March. The European Union is providing the other 25 percent. </p><p>The shipment was the 35th and final delivery of equipment from companies all over the world, including from the United States over the past three years. </p><p>“I think it’s a great accomplishment to finish this,” said Hutch Neilson, head of ITER Fabrication. “The successful completion of the SSEN program is a very important accomplishment both...</p>October 16, 2017Jeanne Jackson DeVoe http://www.pppl.gov/news/2017/10/pppl-completes-shipment-electrical-components-power-site-iter-international-fusionPPPL takes detailed look at 2-D structure of turbulence in tokamakshttp://www.pppl.gov/news/2017/10/pppl-takes-detailed-look-2-d-structure-turbulence-tokamaks
<p>A key hurdle for fusion researchers is understanding turbulence, the ripples and eddies that can cause the superhot plasma that fuels fusion reactions to leak heat and particles and keep fusion from taking place. Comprehending and reducing turbulence will facilitate the development of fusion as a safe, clean and abundant source of energy for generating electricity from power plants around the world.</p><p>At the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), scientists have assembled a large database of detailed measurements of the two dimensional (2-D) structure of edge plasma turbulence made visible by a diagnostic technique known as gas puff imaging. The two dimensions, measured inside a fusion device called a tokamak, represent the radial and vertical structure of the turbulence. </p><p><strong>Step toward fuller understanding</strong></p><p>“This study is an incremental step toward a fuller understanding of turbulence,” said physicist Stewart Zweben, lead author of the research published in the journal <em>Physics of Plasmas</em>. “It could help us understand how turbulence functions as the main cause of leakage of plasma confinement.”</p>...October 13, 2017John Greenwaldhttp://www.pppl.gov/news/2017/10/pppl-takes-detailed-look-2-d-structure-turbulence-tokamaksPPPL and General Atomics team up to make TRANSP code widely availablehttp://www.pppl.gov/news/2017/10/pppl-and-general-atomics-team-make-transp-code-widely-available
<p>Plasma transport analysis, the study of how plasma particles, heat and momentum drift across magnetic field lines, is a necessary first step for understanding how well fusion reactors are performing. Teams of scientists from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and General Atomics (GA) have joined forces to bring PPPL’s premier transport code, TRANSP, to beginning users and experts alike.</p><p>Using the workflow manager OMFIT developed by GA scientists, the team has created a TRANSP module that streamlines data preparation for TRANSP analysis and couples TRANSP to other widely used software. While TRANSP analysis of international tokamak experiments has been available for more than 30 years, the new interface through OMFIT has produced a new user base, modern visualization and increased productivity.</p><p><strong>Expanding the global community</strong></p><p>The result has been expansion of a global community. “From a technical point of view, OMFIT is a workflow manager that can couple physics codes, execute them in complex workflows, and provide them with streamlined interfaces,” says Orso Meneghini, a GA physicist. “Perhaps more...</p>October 6, 2017John Greenwaldhttp://www.pppl.gov/news/2017/10/pppl-and-general-atomics-team-make-transp-code-widely-availableResearch led by PPPL provides reassurance that heat flux will be manageable in ITERhttp://www.pppl.gov/news/2017/09/research-led-pppl-provides-reassurance-heat-flux-will-be-manageable-iter
<p>A major issue facing ITER, the international tokamak under construction in France that will be the first magnetic fusion device to produce net energy, is whether the crucial divertor plates that will exhaust waste heat from the device can withstand the high heat flux, or load, that will strike them. Alarming projections extrapolated from existing tokamaks suggest that the heat flux could be so narrow and concentrated as to damage the tungsten divertor plates in the seven-story, 23,000 ton tokamak and require frequent and costly repairs. This flux could be comparable to the heat load experienced by spacecraft re-entering Earth’s atmosphere.</p><p>New findings of an international team led by physicist C.S. Chang of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) paint a more positive picture. Results of the collaboration, which has spent two years simulating the heat flux, indicate that the width could be well within the capacity of the divertor plates to tolerate.</p><p><strong>Good news for ITER</strong></p><p>“This could be very good news for ITER,” Chang said of the findings, published in August in the journal Nuclear Fusion. “This indicates...</p>September 26, 2017John Greenwaldhttp://www.pppl.gov/news/2017/09/research-led-pppl-provides-reassurance-heat-flux-will-be-manageable-iterPPPL physicist Francesca Poli named ITER Scientist Fellowhttp://www.pppl.gov/news/2017/09/pppl-physicist-francesca-poli-named-iter-scientist-fellow
<p>Physicist Francesca Poli of the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) has been appointed an ITER Scientist Fellow. She will join a network of researchers who have achieved international recognition and will work closely with ITER, an international tokamak under construction in France, to develop the scientific program to be carried out during the fusion device’s lifetime.</p><p>Poli will facilitate installation of TRANSP, the PPPL-developed computer code that is used throughout the world to analyze and predict fusion experiments. Included in her role will be the design of scenarios for the ITER research plan and the training of young researchers on operation of the code.</p><p>“I’m pretty excited,” Poli said of the appointment, which was approved by ITER Director-General Bernard Bigot. “This will allow us to promote TRANSP for ITER and will be good for the Laboratory,” she said. “It will enable us to improve TRANSP by developing new capabilities.”</p><p>For ITER, Poli previously coupled a reduced model of neoclassical tearing modes, a type of plasma instability, to the large and complex TRANSP code. She continues to work with the International...</p>September 21, 2017John Greenwaldhttp://www.pppl.gov/news/2017/09/pppl-physicist-francesca-poli-named-iter-scientist-fellowPhysicists propose new way to stabilize next-generation fusion plasmashttp://www.pppl.gov/news/2017/09/physicists-propose-new-way-stabilize-next-generation-fusion-plasmas
<p>A key issue for next-generation fusion reactors is the possible impact of many unstable Alfvén eigenmodes, wave-like disturbances produced by the fusion reactions that ripple through the plasma in doughnut-shaped fusion facilities called “tokamaks.” Deuterium and tritium fuel react when heated to temperatures near 100 million degrees Celsius, producing high-energy helium ions called alpha particles that heat the plasma and sustain the fusion reactions.</p><p>These alpha particles are even hotter than the fuel and have so much energy that they can drive Alfvén eigenmodes that allow the particles to escape from the reaction chamber before they can heat the plasma. Understanding these waves and how they help alpha particles escape is a key research topic in fusion science.</p><p>If only one or two of these waves are excited in the reaction chamber, the effect on the alpha particles and their ability to heat the fuel is limited. However, theorists have predicted for some time that if many of these waves are excited, they can collectively throw out a lot of alpha particles, endangering the reactor chamber walls and the efficient heating of the fuel.</p><p>Recent experiments...</p>September 11, 2017Raphael Rosenhttp://www.pppl.gov/news/2017/09/physicists-propose-new-way-stabilize-next-generation-fusion-plasmasPPPL has a new interim director and is moving ahead with construction of prototype magnetshttp://www.pppl.gov/news/2017/09/pppl-has-new-interim-director-and-moving-ahead-construction-prototype-magnets
<p>Rich Hawryluk has been appointed interim director of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) while an international search for a permanent director moves forward, Princeton University Vice President for PPPL David McComas announced recently. Hawryluk, who has been heading the NSTX-U Recovery Planning Project, is an internationally-known physicist and a former deputy director of PPPL. </p><p>“Rich has earned my highest respect and the respect of his colleagues and staff at PPPL and of researchers throughout the world for his work as a scientist, project manager, and leader. I am delighted he has agreed to head the Laboratory as we move into the next phase of the NSTX-U recovery Planning Project,” McComas said. </p><p>Hawryluk said that he was grateful for the opportunity to lead the Laboratory where he has worked for more than four decades. “I feel deeply about this place,” he said. “It has given me enormous opportunities to do research, as well as scientific and technical management. I feel it’s incumbent on me to do all I possibly can to give the scientists and the engineers and the staff here exciting and productive scientific...</p>September 8, 2017Jeanne Jackson DeVoe http://www.pppl.gov/news/2017/09/pppl-has-new-interim-director-and-moving-ahead-construction-prototype-magnetsTeam led by graduate student at PPPL produces unique simulation of magnetic reconnectionhttp://www.pppl.gov/news/2017/09/team-led-graduate-student-pppl-produces-unique-simulation-magnetic-reconnection
<p>Jonathan Ng, a Princeton University graduate student at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), has for the first time applied a fluid simulation to the space plasma process behind solar flares northern lights and space storms. The model could lead to improved forecasts of space weather that can shut down cell phone service and damage power grids, as well as to better understanding of the hot, charged plasma gas that fuels fusion reactions.</p><p>The new simulation captures the physics of magnetic reconnection, the breaking apart and snapping together of the magnetic field lines in plasma that occurs throughout the universe. The simulations approximate kinetic effects in a fluid code, which treats plasma as a flowing liquid, to create a more detailed picture of the reconnection process. </p><p>Previous simulations used fluid codes to produce simplified descriptions of reconnection that takes place in the vastness of space, where widely separated plasma particles rarely collide. However, this collisionless environment gives rise to kinetic effects on plasma behavior that fluid models cannot normally capture.</p><p><strong>Estimation of...</strong></p>September 8, 2017John Greenwaldhttp://www.pppl.gov/news/2017/09/team-led-graduate-student-pppl-produces-unique-simulation-magnetic-reconnection15th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems at PPPLhttp://www.pppl.gov/news/2017/09/15th-iaea-technical-meeting-energetic-particles-magnetic-confinement-systems-pppl
<p>The International Atomic Energy Agency (IAEA) held the 15th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems from 5 to 8 September 2017 in Princeton, NJ, USA at PPPL. PPPL physicist Mario Podestà chaired the event.</p><p>The purpose of the meeting was to discuss the status of experimental and theoretical works on suprathermal electrons and ions in a wide variety of magnetic confinement geometries. The meeting covered the formation and transportation of energetic particles, including their confinement properties. It also provided a detailed account of the location of lost energetic particle incidence on first wall components, the collective instabilities they drive, their impact on plasma properties in different operational scenarios, and energetic particles diagnostics. The meeting aimed, in particular, to identify open physics issues and gaps associated with energetic particles in ITER and future fusion power plants.</p>September 5, 2017http://www.pppl.gov/news/2017/09/15th-iaea-technical-meeting-energetic-particles-magnetic-confinement-systems-ppplPPPL physicists essential to new campaign on world’s most powerful stellaratorhttp://www.pppl.gov/news/2017/08/pppl-physicists-essential-new-campaign-world%E2%80%99s-most-powerful-stellarator
<p>Physicists from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) are providing critical expertise for the first full campaign of the world’s largest and most powerful stellarator, a magnetic confinement fusion experiment, the Wendelstein 7-X (W7-X) in Germany. The fusion facility resumes operating on August 28, 2017, and will investigate the suitability of its optimized magnetic fields to create steady state plasmas and to serve as a model for a future power plant for the production of a “star in a jar,” a virtually limitless source of safe and clean energy for generating electricity.</p><p> The W7-X started up in December, 2015, and concluded its initial run in March, 2016. The facility has since been upgraded to prepare for the high-power campaign that is set to begin.</p><p>Deeply involved in the new 15-week run are PPPL physicists Sam Lazerson and Novimir Pablant, who are spending two years at the Max Planck Institute of Plasma Physics in Greifswald, Germany. Lazerson, who previously mapped the W7-X magnetic fields with barn-door sized magnetic coils built by PPPL, heads a task force that will plan and run a series of experiments on the...</p>August 28, 2017John Greenwaldhttp://www.pppl.gov/news/2017/08/pppl-physicists-essential-new-campaign-world%E2%80%99s-most-powerful-stellaratorYoung scientists show off hands-on research projects at PPPLhttp://www.pppl.gov/news/2017/08/young-scientists-show-hands-research-projects-pppl
<p>For Dhruvit Patel, a rising senior majoring in mechanical engineering and physics at Rutgers University, the 10 weeks he spent at the Princeton Plasma Physics Laboratory (PPPL) were a welcome opportunity to do hands-on research.</p><p>He spent the summer working on a nozzle that can be used to coat the inner wall of a tokamak – a plasma fusion device – with liquid metal. But before he even got started, he had to do a lot of research and preparation. </p><p>“I learned the majority of things that really have to happen before you begin the experiment,” he said. “I learned a lot about how to think scientifically.” </p><p>Patel was one of 21 students in the Science Undergraduate Laboratory Internships (SULI) program to take part in an Aug. 16 poster session at the U.S. Department of Energy’s (DOE) PPPL. Also taking part in the poster session were Community College Internship (CCI) program students, engineering interns, and high school interns, bringing the total number of participants to 32.</p>Challenging projects<p>“I’m very proud of them,” said Deedee Ortiz, the Science Education program coordinator, who organizes the internship programs at PPPL. “It’s impressive. They work on...</p>August 24, 2017Jeanne Jackson DeVoe http://www.pppl.gov/news/2017/08/young-scientists-show-hands-research-projects-ppplPPPL physicist discovers that some plasma instabilities can extinguish themselveshttp://www.pppl.gov/news/2017/08/pppl-physicist-discovers-some-plasma-instabilities-can-extinguish-themselves
<p>Physicist Fatima Ebrahimi at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has for the first time used advanced models to accurately simulate key characteristics of the cyclic behavior of edge-localized modes (ELMs), a particular type of plasma instability. The findings could help physicists more fully comprehend the behavior of plasma, the hot, charged gas that fuels fusion reactions in doughnut-shaped fusion facilities called tokamaks, and more reliably produce plasmas for fusion reactions. The findings could also provide insight into solar flares, the eruptions of enormous masses of plasma from the surface of the sun into space.</p><p>Ebrahimi, who reported the work in May in a paper titled, “Nonlinear reconnecting edge localized modes in current-carrying plasmas” in the journal <em>Physics of Plasmas</em>, achieved the results through nonlinear simulation of the instability. “This research both reproduces and explains the burst-like, or quasi-periodic, behavior of ELMS,” said Ebrahimi. “If it occurs in large tokamaks in the future, these bursts could damage some of the machine’s internal components. Understanding them could help scientists...</p>August 24, 2017Raphael Rosenhttp://www.pppl.gov/news/2017/08/pppl-physicist-discovers-some-plasma-instabilities-can-extinguish-themselvesDiscovered: A quick and easy way to shut down instabilities in fusion deviceshttp://www.pppl.gov/news/2017/08/discovered-quick-and-easy-way-shut-down-instabilities-fusion-devices
<p>Scientists have discovered a remarkably simple way to suppress a common instability that can halt fusion reactions and damage the walls of reactors built to create a “star in a jar.” The findings, published in June in the journal <em>Physical Review Letters</em>, stem from experiments performed on the National Spherical Torus Experiment-Upgrade (NSTX-U), at the Department of Energy’s Princeton Plasma Physics Laboratory (PPPL).</p><p>The suppressed instability is called a global Alfvén eigenmode (GAE) — a common wave-like disturbance that can cause fusion reactions to fizzle out. Suppression was achieved with a second neutral beam injector recently installed as part of the NSTX-U upgrade. Just a small amount of highly energetic particles from this second injector was able to shut down the GAEs.</p><p><strong>Akin to a snake or dragon</strong></p><p>Such instabilities are akin to a snake or dragon that swallows its own tail. Stirring up GAEs are the same neutral beam particles that heat the plasma, which are ionized into electrons and ions, or atomic nuclei, inside the gas. Once triggered by these fast ions, the GAEs can rise up and drive them out, cooling the plasma and halting...</p>August 17, 2017John Greenwaldhttp://www.pppl.gov/news/2017/08/discovered-quick-and-easy-way-shut-down-instabilities-fusion-devicesPPPL delivers new key components to help power a fusion energy experimenthttp://www.pppl.gov/news/2017/08/pppl-delivers-new-key-components-help-power-fusion-energy-experiment
<p>Fusion power, which lights the sun and stars, requires temperatures of millions of degrees to fuse the particles inside plasma, a soup of charged gas that fuels fusion reactions. Here on Earth, scientists developing fusion as a safe, clean and abundant source of energy must produce temperatures hotter than the core of the sun in doughnut-shaped facilities called tokamaks. Much of the power needed to reach these temperatures comes from high-energy beams that physicists pump into the plasma through devices known as neutral beam injectors.</p><p>At the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), engineers recently designed and delivered a set of innovative new components for the neutral beam injectors that heat plasma in the DIII-D National Fusion Facility, the tokamak that General Atomics operates for DOE in San Diego.</p><p>The redesigned parts, called pole shields, protect magnets in the injectors from the energetic particles from the beam and will replace units that melted and cracked during previous fusion experiments, resulting in water leaks. The magnets redirect charged atomic nuclei, or ions, in the beams to an ion dump inside the...</p>August 17, 2017John Greenwaldhttp://www.pppl.gov/news/2017/08/pppl-delivers-new-key-components-help-power-fusion-energy-experiment